Always consult a manufacturer SDS. Read our Full Liability Disclaimer
Hazard Level & Hazards:
When we create or update chemical disposal entries, our H-code hazard list is generous. We list hazards that may be just below regular cutoffs and would otherwise normally be unlisted. We do this to provide hobbyists a wider scope of safety risks that may still be relevant, despite normally being omitted. Our GHS icons, however, are congruent with typical legal labeling requirements of the respective chemical.
Low
- H000: Low hazard for normal industrial use
Disposal Method
Keep the chemical in its original packaging. Do not pour down any drains or dispose in the regular trash. The labeled container can be taken to:
- Your local household hazardous waste (HHW) facility. Visit our page on HHW facilities for more information about what to expect at a HHW facility.
- Pool supply stores. Not all of them, but some pool supply stores may accept old, unused chemicals for a small fee or as a courtesy. Call ahead to check.
- Neighbors. If the chemical is still dry and in its original container, it doesn’t really expire. Consider giving it to a neighbor with a pool or posting it on a local community group or forum.
Neutralizing Agent
N/A. For spills: Wear safety goggle and gloves. For dry spills, stop the spread then sweep or vacuum. Try not to stir it up into dust. Put into a labeled HDPE container and follow disposal instructions above. For liquid spills, use an absorbent like kitty litter to soak up the liquid. Place all clean-up materials in a double plastic bag and follow the disposal instructions above.
Storage Precautions
Keep in a sealed HDPE container. Keep the container in a cool dry place.
Ideal Storage Container
HDPE. Review our chemical storage container guide for more information about container types and materials.
Other Names
Isocyanuric acid, CYA, 1,3,5-Triazine-2,4,6-triol, Tricyanic acid, Chlorine Stabilizer, Conditioner, Pool Sunscreen
Additional Tips
- Never use the same scoop or bucket for different chemicals, even if you think you rinsed it out. A few stray granules of Cal-Hypo in a bucket of Cyanuric Acid can start a fire.
- Keep cyanuric acid in a cool, dry place. If it gets wet, it can become reactive or begin to degrade the container.
- Do not add cyanuric acid to the pool skimmer at the same time you are adding chlorine tablets. They can meet in the pipes or the filter and react under pressure.
- Always Add Acid to water, never water to acid. If you are pre-dissolving cyanuric acid, fill the bucket with water first, then add the granules slowly.
- Cyanuric acid is notoriously stubborn in water (2g/L at 25 degrees C). If you need a concentrated aqueous solution, raise the pH. Because CYA is a weak acid, it dissolves much more readily in a basic solution (like adding a bit of sodium hydroxide) to form sodium cyanurate. If you are avoiding water, CYA is soluble in DMSO (Dimethyl sulfoxide) and DMF (Dimethylformamide), which can be useful for non-aqueous reactions.
- If you are experimenting with sublimation or dry heating, be careful. When heated above 320-350 degrees C, cyanuric acid depolymerizes into isocyanic acid (HNCO). Isocyanic acid is a toxic gas and a severe respiratory irritant. Unlike the relatively safe CYA powder, the gaseous byproduct is dangerous. Always perform high-heat experiments in a fume hood or a very well-ventilated outdoor area.
- Cyanuric acid can act as a ligand for transition metals. You can create interesting colorful complexes by reacting sodium cyanurate with metal salts like Copper(II) sulfate or Nickel(II) chloride.
Incompatible Chemicals/Dangerous Combinations
- Calcium Hypochlorite (Ca(ClO)₂) Explosion / Fire – Calcium Hypochlorite is a strong oxidizer. When mixed directly with cyanuric acid, it can lead to a fire or even an explosion in a confined space
- Trichlor/Dichlor Toxic Gas – Trichlor and Dichlor shocks already contain cyanuric acid as a stabilizer. Adding pure cyanuric acid, however, can cause an unpredictable reaction
- Strong Acids (Like Muriatic Acid) Toxic Fumes – Adding a strong acid like Muriatic Acid (HCl) to cyanuric acid can cause it to decompose. This reaction releases toxic fumes.